Here is one for you, if you already known it, as it is your hobby....let someone else have shot.
(I have plenty more where those come from.)

Heidi Greenfingers has a cottage situated on a well treed lot in Northern Scotland. She enjoys keeping her lot in top condition by fertilizing, pruning and removing deadwood and broken branches. However, Heidi has rather strange habit regarding her little forest. Every once in a while she'll chop down a perfectly healthy tree and put it in a large pot. She'll water the tree and fertilize it etc. and a short time later when she grows tired of it, she burns it. Could there be any rational explanation for this seemingly strange behaviour?